/Engine/Plugins/Online/OnlineSubsystemUtils/Source/OnlineSubsystemUtils/Public/PartyBeaconClient.h
Sends a request to the remote host. If there is an existing reservation it will update it in the host's session. Otherwise it will allow the specified members to reserve space in the host's session. Note this request is async.
true if the request able to be sent, false if it failed to send
virtual bool RequestAddOrUpdateReservation ( const [FString](API\Runtime\Core\Containers\FString) & ConnectInfoStr, const [FString](API\Runtime\Core\Containers\FString) & InSessionId, const [FUniqueNetIdRepl](API\Runtime\Engine\GameFramework\FUniqueNetIdRepl) & RequestingPartyLeader, const [TArray](API\Runtime\Core\Containers\TArray)< [FPlayerReservation](API\Plugins\OnlineSubsystemUtils\FPlayerReservation) > & PartyMembers )